US20110141909A1 - Wireless terminal positioning system, method of positioning wireless terminal, environment measurment system, facility management system, method of measuring environment, and method of deciding destination of wireless mobile terminal - Google Patents

Abstract

To obtain a method of positioning a wireless terminal capable of obtaining the position of each communication terminal by measuring distances with installed communication terminals each other without fixedly installing a base station.

A positioning management terminal100 includes a positioning object decision section130 that selects a terminal to be positioned, which is a positioning object, and a positioning standard terminal, whose position is known, among the wireless terminals200; a positioning management section120 that requires distance information between the terminal to be positioned and the positioning standard terminal; and a position calculation section140 that calculates the position of the terminal to be positioned. The positioning management section120 requires distance information from the positioning standard terminal selected by the positioning object decision section130 to the terminal to be positioned selected by the positioning object decision section130. The position calculation section140 calculates the position of the terminal to be positioned using the distance information and position information of the positioning standard terminal.

Description

TECHNICAL FIELD
• The present invention relates to a wireless terminal positioning system that calculates the position of a wireless terminal and a method of the calculation, and to a technique that measures environmental conditions.
BACKGROUND ART
• In a small-scale wireless network system supposed to be used mainly in a building facility and in a home such as a sensor network system, a technique has been developed that measures the position of a wireless communication terminal with high precision.
• Since a GPS (Global Positioning System) signal cannot be received in the building facility and in the home, a system is known that measures a distance and a distance difference among a plurality of terminals to estimate the position using a time of arrival (TOA) of radio waves from a base station whose position is known, a time difference of arrival (TDOA) of radio waves, and a radio wave receiving intensity.
• An assumption is made that coordinates of a base station are known in advance in the above. In order to save time and effort to set coordinates of the base station, a technique is proposed such that “at least (N+1) base stations (N=1 to 3) and positioning servers are provided. The distances among at least (N+1) base stations are calculated. Relative coordinates of each base station are obtained. The obtained relative coordinates are evaluated. A switching to the terminal positioning processing for obtaining the position of the terminal is judged. The position of the terminal is obtained using a propagation time of the wireless signal that is transmitted and received between the terminal and the base station and relative coordinates among the obtained base stations.”
• On the other hand, in a wireless communication system in which a number of terminals are installed for buildings and homes in general, since an output is suppressed so as to be able to be driven by batteries, causing a limit in a communication range to be from approximately several meters to several tens of meters.
• As a result, like ZigBee (trademark), for example, a multi-hop network technique is known that enables communications in a wider area in which an intermediate communication terminal relays data for terminals to which no radio waves can reach directly.
• In recent years, in buildings and factories, sensors are installed at various locations and an environment measurement system is employed that measures environmental conditions such as temperature, humidity, and luminance in order to properly control air conditioning and lighting apparatuses. For example, in an air conditioning system, an air conditioning apparatus is controlled such that the measurement value of a temperature sensor installed at the air supply opening and the remote controller of the indoor unit of the air conditioning apparatus becomes a set temperature.
• Further, in order to carefully control the apparatus according to the request by residents and the temperature distribution of the space, and to precisely evaluate energy performance of the building, environmental conditions need to be measured at more measurement points.
• In order to measure environmental conditions at a number of measurement points, in general, a number of sensors need to be installed at a number of places by increasing the number of sensors to be measured. Therefore, increase in cost and complicated management become challenges.
• In relation to the above environment measurement, as a technique intended “to improve precision and accuracy of plant diagnosis and reduce variations in inspection by making the sensor to be self-advancing to obtain a number of process values at many points in order to measure the facility in the plant and process values of the area”, such a technique is proposed that “a sensor detects the facility constituting a plant or a process value of a predetermined area. The sensor is provided with drive means that moves to a desired position in the facility or a predetermined area to detect process values.” (Patent Literature 2)
• Patent Literature 1 Japanese Unexamined Patent Application Publication No. 2007-248362
• Patent Literature 2 Japanese Unexamined Patent Application Publication No. 2003-130695
SUMMARY OF INVENTIONTechnical Problem
• According to a conventional method, in a system where a number of communication terminals are installed having low output over a wide area and communication is performed by relaying in the middle to terminals incapable of direct communication, a number of base stations to be a standard for positioning need to be installed so as to cover the area where the network system is installed.
• In a method that automatically obtains a relative position between base stations like theabove Patent Literature 1, all the base stations need to communicate each other, therefore, it is difficult to decide the relative position of the base station in the area beyond a communication range of a base station.
• The self-advancing sensor according to theabove Patent Literature 2 moves along piping and runs on a rail laid in advance. Accordingly, a rail guide and the like to be a reference when controlling a moving position of the self-advancing sensor has to be installed in advance, resulting costly.
• The present invention is done to solve the above problems and its object is to obtain a method for positioning a wireless terminal capable of obtaining the position of each communication terminal by measuring a distance among installed communication terminals with no base station being installed fixedly.
• Another object is to provide a method for measuring environmental conditions at a number of measurement points with less cost by a few sensor terminals.
Solution to Problem
• A wireless terminal positioning system according to the present invention has a positioning management terminal that manages one or a plurality of wireless terminals and the positioning of the wireless terminals. The positioning management terminal includes: a positioning object decision section that selects a terminal to be positioned, which is a positioning object, and a positioning standard terminal, whose position is known, among the above wireless terminals; a positioning management section that requires distance information between the terminal to be positioned and the positioning standard terminal; and a position calculation section that calculates the position of the terminal to be positioned. The wireless terminal includes a distance measurement section that measures the distance from the adjacent terminal at which wireless signals of the wireless terminal arrives, and a communication section that transmits measurement results of the distance measurement section to the positioning management terminal. The positioning management terminal requires distance information from the positioning standard terminal selected by the positioning object decision section to the terminal to be positioned selected by the positioning object decision section. The position calculation section calculates the position of the terminal to be positioned using the distance information and position information of the positioning standard terminal.
• An environment measurement system according to the present invention measures environmental conditions of a measurement object space. There are provided: a fixed sensor terminal fixedly installed in the measurement object space; a mobile sensor terminal that moves in the measurement object space; and positioning means that measures the position of the mobile sensor terminal. The fixed sensor terminal measures environmental conditions surrounding the installation place of the self terminal. The fixed sensor terminal and the mobile sensor terminal transmit or receive signals for positioning the mobile sensor terminal. The positioning means positions the mobile sensor terminal using the signals. The mobile sensor terminal measures environmental conditions around the self terminal while grasping the position of the self terminal in the measurement object space using the positioning results.
Advantageous Effects of Invention
• In the wireless terminal positioning system according to the present invention, a terminal to be positioning and a positioning standard terminal are selected in order and distance information is obtained. Based on the position information, the position of the wireless terminal is calculated.
• Accordingly, there is no need to install a base station fixedly. Wireless terminals measure distance each other in order and distance information is collected, thus enabling to obtain positions of wireless terminals installed over a wide range.
• In the environment measurement system according to the present invention, the mobile sensor terminal measures environmental conditions while grasping the position of the self terminal to move in the measurement object space. Thereby, it becomes possible to measure environmental conditions of a number of measurement points only by a few mobile sensor terminals while moving.
• Since a fixed sensor terminal is available as a standard of position detection, there is no need to lay a guide such as a rail for controlling movement position of the mobile sensor terminal, being advantageous over cost.
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1 is a configuration diagram of a wireless positioning system ofEmbodiment 1.
• FIG. 2 is a function block diagram of apositioning management terminal100 ofEmbodiment 1.
• FIG. 3 is a function block diagram of awireless terminal200 ofEmbodiment 1.
• FIG. 4 is an illustration diagram of procedure in which adistance measurement section220 of thewireless terminal200 performs distance measurement.
• FIG. 5 is a configuration diagram of a range-findingdata request packet500.
• FIG. 6 is a configuration diagram of a range-findingdata response packet600.
• FIG. 7 is a configuration diagram of awireless terminal list700 that a terminalinformation storage section150 stores.
• FIG. 8 is a conceptual diagram showing a state in which the position of thewireless terminals200 is determined in order in the wireless positioning system ofEmbodiment 1.
• FIG. 9 is an entire operation sequence of the wireless positioning system ofEmbodiment 1.
• FIG. 10 is a flow chart illustrating details of step S901 ofFIG. 9.
• FIG. 11 is a function block diagram of the wireless terminal ofEmbodiment 2.
• FIG. 12 is an operation sequence diagram when thewireless terminal200areceives an adjacent terminaldata request packet1300.
• FIG. 13 is a configuration diagram of the adjacent terminaldata request packet1300.
• FIG. 14 is a configuration diagram of an adjacent terminaldata response packet1400.
• FIG. 15 is a flow chart of positioning procedure ofEmbodiment 2.
• FIG. 16 is a configuration diagram of the wireless positioning system ofEmbodiment 3.
• FIG. 17 is a function block diagram of amobile wireless terminal300.
• FIG. 18 is an entire operation sequence of the wireless positioning system ofEmbodiment 3.
• FIG. 19 is a sequence diagram showing procedure in which relative positions of thewireless terminals200 of (N+1) or more are obtained and stored inposition information702.
• FIG. 20 is a configuration diagram of an environment measurement system of Embodiment 15.
• FIG. 21 is a functional block diagram of a fixed sensor terminal101.
• FIG. 22 is a functional block diagram of amobile sensor terminal2200.
• FIG. 23 is a diagram illustrating procedure for awireless positioning section2213 to calculate the distance between themobile sensor terminal2200 and a fixedsensor terminal2100.
• FIG. 24 is a diagram illustrating a method for thewireless positioning section2213 to calculate the position of themobile sensor terminal2200.
• FIG. 25 is an operation flow for themobile sensor terminal2200 to measure environmental conditions.
• FIG. 26 is a configuration diagram of an environment measurement system of Embodiment 16.
• FIG. 27 is a configuration diagram of an environment measurement system of Embodiment 17.
• FIG. 28 is a diagram illustrating the state in which themobile sensor terminal2200 switches a role of the self terminal.
• FIG. 29 is an operation flow for a positiondetection object terminal2902 to measure environmental conditions.
• FIG. 30 is a diagram showing the state in which a measurement object space is divided.
• FIG. 31 is a configuration diagram of themobile sensor terminal2200 of Embodiment 21.
• FIG. 32 is a configuration diagram of a facility management system of Embodiment 22.
REFERENCE SIGNS LIST
• 100 positioning management terminal
• 110 communication section
• 120 positioning procedure management section
• 130 positioning object decision section
• 140 position calculation section
• 150 terminal information storage section
• 200a-200jwireless terminal
• 210 communication section
• 220 distance measurement section
• 230 range-finding data processing section
• 240 adjacent terminal search section
• 250 adjacent terminal data processing section
• 300 mobile wireless terminal
• 500 range-finding data request packet
• 501 range-finding data request identifier
• 502 transmission source terminal address
• 503 terminal address to be positioned
• 504 number of range-finding terminal
• 505 range-finding object terminal address
• 600 range-finding data response packet
• 601 range-finding data response identifier
• 602 terminal address to be positioned
• 603 transmission destination terminal address
• 604 number of range-finding terminal
• 605 range-finding object address
• 606 range-finding information
• 700 wireless terminal list
• 701 terminal address
• 702 position information
• 703 adjacent terminal list
• 704 terminal address
• 705 distance information
• 1300 adjacent terminal data request packet
• 1301 adjacent terminal data request identifier
• 1302 transmission source terminal address
• 1303 search source terminal address
• 1400 adjacent terminal data response packet
• 1401 adjacent terminal data response identifier
• 1402 search source terminal address
• 1403 transmission destination terminal address
• 1404 number of adjacent terminal
• 1405 adjacent terminal address
• 2100 fixed sensor terminal
• 2100a-2100cfixed sensor terminal
• 2110 terminal control section
• 2111 wireless communication section
• 2112 environment measurement section
• 2200 mobile sensor terminal
• 2210 terminal control section
• 2211 wireless communication section
• 2212 environment measurement section
• 2213 wireless positioning section
• 2214 self position control section
• 2215 drive section
• 2701 window
• 2702 gateway
• 2901 position detection standard terminal
• 2902 position detection object terminal
• 3101 typical point
• 3201 mobile cart
• 3202 control module
• 3203 support table
• 3204 sensor module
• 3300 facility management apparatus
• 3301 facility management section
• 3302 wireless communication section
DESCRIPTION OFEMBODIMENTSEmbodiment 1
• FIG. 1 is a configuration diagram of a wireless positioning system ofEmbodiment 1.
• The wireless positioning system ofEmbodiment 1 includes one or a plurality ofpositioning management terminals100 andwireless terminals200ato200j.
• Thepositioning management terminal100 manages a positioning process that measures positions ofwireless terminals200ato200j.Specific procedures will be described usingFIGS. 8 to 10 to be mentioned later.
• Thewireless terminals200ato200jare a communication terminal having a wireless communication function.
• In the following description, alphabetical subscripts will be added when differentiating thewireless terminals200ato200j.In a generic explanation, they are called awireless terminal200. Each function section provided with thewireless terminal200 is the same.
• FIG. 2 is a function block diagram of apositioning management terminal100 ofEmbodiment 1.
• Apositioning management terminal100 includes acommunication section110, a positioningprocedure management section120, a positioningobject decision section130, aposition calculation section140, and a terminalinformation storage section150.
• Thecommunication section110 performs wireless communication with thewireless terminal200.
• The terminalinformation storage section150 holds awireless terminal list700 in the wireless positioning system. Thewireless terminal list700 will he described again inFIG. 7 to be mentioned later.
• Theposition calculation section140 calculates a position in the Nth-dimension space of thewireless terminal200, that is Nth-dimension coordinates, from distances between at least (N+1) wireless terminals200 (N is a dimension of the position to be calculated, N=1 to 3) whose positions are known and thewireless terminal200 to be the object for deciding the position.
• In the following explanations, thewireless terminal200 whose position is known is referred to as a “positioning standard terminal” and thewireless terminal200 to be an object for deciding the position is referred to as a “terminal to be positioned”.
• A positioningprocedure management section120 and a positioningobject decision section130 specify whichwireless terminals200 are to be the positioning standard terminal and the terminal to be positioned. Details will be described later.
• The positioningprocedure management section120 manages communication with eachwireless terminal200 for positioning, position calculation of thewireless terminal200 by aposition calculation section140, and procedure like selection of the positioning standard terminal and the terminal to be positioned by the positioningobject decision section130 to manage positioning operation in the present wireless positioning system.
• The positioningobject decision section130 decides thewireless terminal200 to be an object for next positioning and the wireless terminal200 (positioning standard terminal) to be a standard for positioning when thewireless terminal200 is made to be the terminal to be positioned.
• As for a decision technique to decide which wireless terminal be the terminal to be positioned and the positioning standard terminal, descriptions will be given later.
• FIG. 3 is a function block diagram of awireless terminal200 ofEmbodiment 1.
• Thewireless terminal200 includes acommunication section210, adistance measurement section220, and a range-findingdata processing section230.
• Thecommunication section210 performs wireless communication with thepositioning management terminal100 andother wireless terminals200.
• Thedistance measurement section220 measures the distance between twowireless terminals200 using wireless communication. Procedure for distance measurement betweenwireless terminals200 will be explained inFIG. 4 to be mentioned later.
• The range-findingdata processing section230 transmits and receives range-finding data request packet and range-finding response packet between thewireless terminal200 and thepositioning management terminal100 via thecommunication section210. Further, thesection230 transmits and receives range-finding data request packet and range-finding response packet inFIG. 4 to be mentioned later.
• The range-findingdata processing section230 can deliver range-finding data request packet and range-finding response packet via thecommunication section210 to thewireless terminal200 and thepositioning management terminal100 to which no wireless signal is directly delivered by a multi-hop communication.
• Thecommunication section110 of thepositioning management terminal100 and the communication section.210 of thewireless terminal200 perform packet communication with thepositioning management terminal100 or thewireless terminal200 to which wireless signals are directly delivered.
• Thecommunication section210 makes it possible to transfer packets to thepositioning management terminal100 and thewireless terminal200 to which no wireless signal is directly delivered by relaying packets toother wireless terminals200 to transmit them.
• In order to relay packets to thepositioning management terminal100 and thewireless terminal200 to which no wireless signal is directly delivered, thecommunication section110 and thecommunication section210 utilize a multi-hop network protocol such as ZigBee.
• FIG. 4 is an illustration diagram of procedure in which thedistance measurement section220 of thewireless terminal200 performs distance measurement. Here, an example is given in which thewireless terminal200ameasures the distance from thewireless terminal200b.Descriptions will be given to each step ofFIG. 4 as follows.
• (S401)
• The distance measurement section220aof thewireless terminal200atransmits a range-finding request packet to thewireless terminal200bvia thecommunication section210.
• On receiving the range-finding request packet, the distance measurement section220bof thewireless terminal200btransmits a range-finding response packet to thewireless terminal200aafter a predetermined processing time being elapsed.
• On receiving the range-finding response packet, the distance measurement section220aof thewireless terminal200ameasures a response time from the transmission of the range-finding request packet to the receipt of the range-finding response packet.
• Time measurement from the transmission of the range-finding request packet to the receipt of the range-finding response packet is performed such that a counter timer is started when transmitting the range-finding request packet, the counter is stopped when receiving the range-finding response packet, then the time value of the counter is read.
• (S402)
• The distance measurement section220aof thewireless terminal200asubtracts a predetermined processing time of thewireless terminal200bfrom the receipt of the range-finding request packet to the transmission of the range-finding response packet based on the response time in step S401 to calculate a radio wave propagation time between thewireless terminals200aand200b.
• (S403)
• The distance measurement section220aof thewireless terminal200aobtains the distance between thewireless terminals200aand200bby multiplying the radio wave propagation time by the speed of light.
• When transmitting and receiving range-finding request and range-finding response, thecommunication section210 can measure more accurate distance because using a ultra wide band impulse wireless signal that transmits an impulse signal, response time can be measured accurately.
• FIG. 5 is a configuration diagram of the range-findingdata request packet500. The range-findingdata request packet500 is the packet that is intended to request transmission of range-finding results of thewireless terminal200 that received thepacket500.
• The range-findingdata request packet500 includes a range-findingdata request identifier501, a transmission sourceterminal address502, aterminal address503 to be positioned, anumber504 of range-finding terminal, and a range-findingobject terminal address505.
• In the range-findingdata request identifier501, an identifier is stored that shows that the relevant packet is the range-finding data request packet.
• In the transmission sourceterminal address502, the transmission source terminal address of the relevant packet is stored.
• In theterminal address503 to'be positioned, the terminal address to be positioned is stored.
• In thenumber504 of range-finding terminal, the number of terminals of range-finding object is stored.
• In the range-findingobject terminal address505, the range-finding object terminal address is stored for as many as the number shown by thenumber504 of range-finding terminal.
• FIG. 6 is a configuration diagram of the range-findingdata response packet600. The range-findingdata response packet600 is the response packet corresponding to the range-findingdata request packet500.
• The range-findingdata response packet600 includes a range-findingdata response identifier601, a terminal address to be positioned602, a transmissiondestination terminal address603, anumber604 of range-finding terminal, a range-findingobject terminal address605, and range-findinginformation606.
• In the range-findingdata response identifier601, an identifier is stored that shows that the relevant packet is the range-finding data response packet.
• In the terminal address to be positioned602, the terminal address to be positioned is stored.
• In the transmissiondestination terminal address603, the transmission destination terminal address of the relevant packet is stored.
• In thenumber604 of range-finding terminal, the number of terminals of range-finding object is stored.
• In the range-findingobject terminal address605, the range-finding object terminal address is stored for as many as the number shown by thenumber604 of range-finding terminal.
• In the range-findinginformation606, range-finding results are stored for each range-finding object terminal.
• When thewireless terminal200 receives the range-finding request packet, thedistance measurement section220 performs range-finding between thewireless terminals200 designated by the range-findingobject terminal address505 of the range-finding request packet.
• Next, the range-findingdata processing section230 generates the range-finding response packet to transmit it to the transmission source of the range-finding request packet based on the range-finding results performed by thedistance measurement section220.
• FIG. 7 is a configuration diagram of awireless terminal list700 that a terminalinformation storage section150 stores.
• Thewireless terminal list700 includes a terminal address701,position information702, and an adjacentterminal list703.
• The adjacentterminal list703 includes aterminal address704 anddistance information705.
• In the terminal address701, the address of thewireless terminal list700 is stored. Here, the address is described in a simple form made only of the number of the wireless terminal.
• In theposition information702, position coordinates of thewireless terminal200 are stored identified by the terminal address701. Here, example is shown in which three-dimension coordinates are stored.
• In the adjacentterminal list703, an adjacent terminal list is stored identified by the terminal address701.
• In theterminal address704, the adjacent terminal address is stored.
• In thedistance information705, the distance between the adjacent terminal identified by theterminal address704 and the relevant wireless terminal.
• In theposition information702, the adjacentterminal list703, anddistance information705, it is allowable to store that it is undefined.
• The holding method is not limited thereto if the above information can be held in full measure.
• Thecommunication section110, positioningprocedure management section120,position calculation section140, positioningobject decision section130, and terminalinformation storage section150 owned by thepositioning management terminal100 and thecommunication section210,distance measurement section220, and range-findingdata processing section230 owned by thewireless terminal200 can be configured using such as an LSI (Large Scale Integration), ROM (Read Only Memory), and RAM (Random Access Memory), on which a wireless transmission and reception circuit is implemented.
• Alternatively, equivalent functions can be configured by operation devices such as a microcomputer and software specifying its operation.
• Components of a singlepositioning management terminal100 orwireless terminal200 may be configured by being distributed into the terminals such as a plurality of microcomputers and personal computers. It is the same for embodiments below.
• Descriptions have been given to each configuration of the wireless positioning system according toEmbodiment 1 in the above.
• Next, operations will be explained thereof.
• In the explanation ofEmbodiment 1 as follows, the terminal address of the adjacent terminal of eachwireless terminal200 is supposed to be held in the adjacentterminal list703 of the terminalinformation storage section150 of thepositioning management terminal100 in advance.
• The terminal address701 of the adjacent terminal of eachwireless terminal200 is configured, for example, by manual input in advance. Alternatively, all terminals are supposed to be installed within a area capable of communication, for example, and the terminal addresses of all thewireless terminals200 except the self terminal may be configured for the adjacentterminal list703 corresponding to eachwireless terminal200.
• Similarly, eachwireless terminal200 is installed in consideration of the communication distance, and apredetermined wireless terminal200 may be configured in the adjacentterminal list703.
• In the explanation below, positions of at least (N+1)wireless terminals200 are supposed to be configured in theposition information702 of the corresponding terminal address701 in the terminalinformation storage section150 of thepositioning management terminal100.
• Alternatively, positions of (N+1) ormore wireless terminals200 are decided in advance, and eachwireless terminal200 may be placed at that position. Among a plurality of the placedwireless terminals200, positions of (N+1) or more terminals may be manually input and configured.
• FIG. 8 is a conceptual diagram showing a state in which the position of eachwireless terminal200 is determined in order in the wireless positioning system ofEmbodiment 1. Thepositioning management terminal100 is abbreviated.
• The upper diagram ofFIG. 8 shows the adjacent terminal list703cof acertain wireless terminal200cwhose terminal address701 is “3” at the time of a k-th positioning. The terminal to be positioned and the positioning standard terminal selected by thepositioning management terminal100 are shown as well.
• The lower diagram ofFIG. 8 shows the adjacentterminal list703dof thewireless terminal200dwhose terminal address701 is “4” at the time of the (k+1)-th positioning as well. The terminal to be positioned and the positioning standard terminal selected by thepositioning management terminal100 are shown by signs in the diagram.
• In the k-th state (upper diagram ofFIG. 8),position information702 of thewireless terminals200b,200e,200f,and200iof the terminal addresses [2], [5], [6], and [9] is defined (the terminal in banding pattern) in the adjacent terminal list703cof thewireless terminal200cwhose terminal address701 is “3”.
• That is, upon calculating the three-dimension coordinates, position information of at least 3+1=4 adjacent terminals has been defined.
• Therefore, the positioningobject decision section130 of thepositioning management terminal100 selects thewireless terminal200cwhose terminal address is “3” as the terminal to be positioned (a filled terminal) Thewireless terminals200b,200e,200f,and200iof the terminal addresses [2], [5], [6], and [9] are selected as positioning standard terminals (the terminal in banding pattern).
• The positioningprocedure management section120 of thepositioning management terminal100 obtainsdistance information705 between the terminal to be positioned (thewireless terminal200c) and the positioning standard terminals (thewireless terminals200b,200e,200f,and200i). Theposition calculation section140 calculates the position of the terminal to be positioned (thewireless terminal200c) using thedistance information705.
• Similarly, in the (k+1)-th state at the time of positioning,position information702 of thewireless terminals200b,200c,200e,and200fof the terminal addresses [2], [3], [5], and [6] is defined (the terminal in banding pattern) in the adjacentterminal list703dof thewireless terminal200dwhose terminal address701 is “4”.
• Therefore, the positioningobject decision section130 of thepositioning management terminal100 selects thewireless terminal200dwhose terminal address701 is “4” as the terminal to be positioned (a filled terminal). Thewireless terminals200b,200c,200e,and200fof the terminal addresses [2], [3], [5], and [6] are selected as positioning standard terminals (the terminal in banding pattern).
• The positioningprocedure management section120 of thepositioning management terminal100 obtainsdistance information705 between the terminal to be positioned (thewireless terminal200d) and the positioning standard terminals (thewireless terminals200b,200c,200e,and200f). Theposition calculation section140 calculates the position of the terminal to be positioned (thewireless terminal200d) using thedistance information705.
• FIG. 9 is an entire operation sequence of the wireless positioning system ofEmbodiment 1.
• Descriptions will be given to each step ofFIG. 9. Here, each operation under the state of the upper diagram ofFIG. 8 will be explained as an example.
• (S901)
• The positioningobject decision section130 of thepositioning management terminal100 refers to information of thewireless terminal list700 that the terminalinformation storage section150 holds to select the next object to be positioned as the terminal to be positioned among thewireless terminals200 whoseposition information702 is undefined in thewireless terminal list700. In the example ofFIG. 8, for example, thewireless terminal200cis selected.
• The positioningobject decision section130 selects at least (N+1) positioning standard terminals for positioning the terminal to be positioned among thewireless terminals200 whoseposition information702 is defined in thewireless terminal list700.
• (S902)
• The positioningprocedure management section120 transmits the range-findingdata request packet500 to the terminal to be positioned (thewireless terminals200c) notified by the positioningobject decision section130 via thecommunication section110.
• In the range-findingobject terminal address505 of the range-findingdata request packet500, the terminal address of the positioning standard terminal (thewireless terminals200b,200e,200f,and200i) notified by the positioningobject decision section130 is stored.
• (S903ato S903d)
• The distance measurement section220cof the terminal to be positioned (thewireless terminals200c) that received the range-findingdata request packet500 performs positioning in order for the positioning standard terminals (here, thewireless terminals200b,200e,200f,and200i) stored in the range-findingobject terminal address505 of the range-findingdata request packet500.
• The range-finding data processing section230ccollectively stores positioning results of the distance measurement section220cinto the range-findingdata response packet600 to transmit them to thepositioning management terminal100.
• (S904)
• Theposition calculation section140 of thepositioning management terminal100 obtains theposition information702 of the positioning standard terminal selected by the positioningobject decision section130 and thedistance information705 between the terminal to be positioned and the positioning standard terminal selected by the positioningobject decision section130.
• Next, theposition calculation section140 calculates the position of the terminal to be positioned (the wireless terminal200) using theposition information702 and thedistance information705.
• Calculated position of the terminal to be positioned (the wireless terminal200) is stored in theposition information702 corresponded by the terminalinformation storage section150.
• According to the above procedure (S902 to S904), the position of the terminal to be positioned (the wireless terminal200) selected by the positioningobject decision section130 is decided.
• (S905)
• The positioningprocedure management section120 judges whether theposition information702 of all thewireless terminals200 in thewireless terminal list700 has been defined or not.
• If theposition information702 of all thewireless terminals200 has been defined, the positioningprocedure management section120 concludes positioning. If theposition information702 of all thewireless terminals200 has not been defined, the process returns to step S901 to repeat the same processing.
• FIG. 10 is a flow chart illustrating details of step S901 ofFIG. 9. Descriptions will be given to each step ofFIG. 10.
• (S1001)
• The positioningobject decision section130 of thepositioning management terminal100 selects thewireless terminals200 in order in thewireless terminal list700 stored by the terminalinformation storage section150.
• (S1002)
• The positioningobject decision section130 judges whether theposition information702 of thewireless terminals200 selected in step S1001 has been defined or not. If not yet defined, proceed to step S1003. If defined, return to step S1001 to select thenext wireless terminal200. This step is intended for searching a candidate of the terminal to be positioned.
• (S1003)
• With regard to thewireless terminal200 whoseposition information702 has not been defined, the positioningobject decision section130 refers to the adjacentterminal list703 of thewireless terminal200. Next, the positioningobject decision section130 judges whether at least (N+1) ormore wireless terminals200 whoseposition information702 has been defined are included in the adjacentterminal list703.
• If (N+1) or more have been defined, proceed to step S1004. If not, return to step S1001 to select thenext wireless terminal200.
• (S1004)
• The positioningobject decision section130 selects thewireless terminals200 whoseposition information702 has not been defined as the terminal to be positioned.
• (S1005)
• The positioningobject decision section130 selects any of (N+1)wireless terminals200 among adjacent terminals of the terminal to be positioned selected in step S1004 as the positioning standard terminal.
• If (N+1) or more adjacent terminals whoseposition information702 has been defined are not included, the same judgment as S1001 and S1002 is performed for thenext wireless terminals200 whoseposition information702 has been defined.
• Details of step S901 are explained in the above.
• As described inFIG. 10, by selecting the terminal to be positioned and the positioning standard terminal, the terminal to be positioned can be selected that can define the position based on range-finding data.
• The positioningobject decision section130 informs the positioningprocedure management section120 of the terminal addresses701 of the selected terminal to be positioned and the positioning standard terminal.
• Operation of the wireless positioning system according toEmbodiment 1 is explained in the above.
• As mentioned above, according toEmbodiment 1, the position of thewireless terminals200 whoseposition information702 has not been defined is calculated in order bydistance information705 between thewireless terminals200 whoseposition information702 has been defined.
• Thereby,position information702 of all thewireless terminals200 can be calculated.
• According toEmbodiment 1, thepositioning management terminal100 calculatesposition information702 of all thewireless terminals200 while selecting the positioning standard terminal and the terminal to be positioned in order.
• Therefore, without separately installing base stations over a wide area and configuring their positions in advance, it is possible to calculateposition information702 of eachwireless terminals200 based on position information of already installedwireless terminals200.
• According toEmbodiment 1, with thewireless terminals200 incapable of direct communication with each other, thepositioning management terminal100 transmits the range-findingdata request packet500 to thewireless terminals200 selected as the terminal to be positioned by a multi-hop communication.
• Thewireless terminal200 that received the range-findingdata request packet500 transmits the range-findingdata response packet600 including the measureddistance information606 to thepositioning management terminal100 again by the multi-hop communication.
• Thereby, since thepositioning management terminal100 can finalizeposition information702 of thewireless terminals200 in order,position information702 of all thewireless terminals200 can be decided in the wireless positioning system in which thewireless terminals200 are installed over a wide range.
• InEmbodiment 1, mutual distance of all thewireless terminals200 is not measured but only the distance between the terminal to be positioned and the positioning standard terminal selected by thepositioning management terminal100 may be measured. Thereby, communication amount for range-finding can be reduced.
• That is, withN wireless terminals200, frequency of communication in proportion to N squared is necessary for measuring the distance among all the adjacent terminals. However, inEmbodiment 1, frequency of communication in proportion to N will suffice.
• Thus, communication amount can be drastically reduced required for measuring positions of a number of units.
• InEmbodiment 1, thepositioning management terminal100 calculatesposition information702 of all thewireless terminals200 while selecting the positioning standard terminal and the terminal to be positioned in order.
• Therefore, there is no distinction between the base station and the terminal to be positioned like a conventional positioning method.
• Accordingly, by providing devices installed at a suitable interval in a building facility, for example, with thewireless terminal200 according toEmbodiment 1, it becomes possible to obtain the position of each device without separately installing a base station.
Embodiment 2
• FIG. 11 is a function block diagram of thewireless terminal200 ofEmbodiment 2. Thewireless terminal200 ofEmbodiment 2 newly includes the adjacentterminal search section240 and the adjacent terminaldata processing section250 in addition to thewireless terminal200 ofEmbodiment 1. The other configurations are the same withFIG. 3.
• The adjacentterminal search section240 obtains information on the adjacent terminal of thewireless terminal200. The procedure to obtain information on the adjacent terminal will be explained inFIG. 12 to be mentioned later.
• The adjacent terminaldata processing section250 transmits and receives the adjacent terminaldata request packet1300 and the adjacent terminaldata response packet1400 described inFIGS. 13 and 14 to be mentioned later with thepositioning management terminal100. The adjacent terminaldata processing section250 also transmits and receives the adjacent terminal search packet and the adjacent terminal search response packet described in FIG.12 to be mentioned later.
• The adjacent terminaldata processing section250 can deliver the adjacent terminaldata request packet1300 and the adjacent terminaldata response packet1400 via thecommunication section210 to thewireless terminal200 and thepositioning management terminal100 to which no wireless signal is directly delivered by multi-hop communication.
• On receiving the adjacent terminaldata request packet1300, the adjacent terminaldata processing section250 of thewireless terminal200 stores the address of the adjacent terminal that the adjacentterminal search section240 obtained into the adjacent terminaldata response packet1400 to transmit the same to the transmission source of the adjacent terminaldata request packet1300.
• The adjacentterminal search section240 and the adjacent terminaldata processing section250 can be configured using LSI, ROM, RAM and the like that implemented a wireless transmission and reception circuit.
• Alternatively, similar functions can be configured by operation devices such as microcomputers and software defining their operations.
• FIG. 12 is an operation sequence diagram when thewireless terminal200areceives an adjacent terminaldata request packet1300.
• The adjacent terminal data processing section250aof thewireless terminal200areceives adjacent terminaldata request packet1300 described inFIG. 13 to be mentioned later through thecommunication section210.
• Next, the adjacent terminal search section240atransmits the adjacent terminal search packet by synchronous transmission.
• The adjacent terminaldata processing section250 of the wireless terminal200 (here,200bto200d) that received the adjacent terminal search packet transmits the adjacent terminal search response packet to thewireless terminal200a.
• The adjacentterminal search section240 of thewireless terminal200a,which is a search source, holds the transmission source address of the adjacent terminal search response packet in a memory, etc.
• Thereby, thewireless terminal200acan obtain information on the adjacent terminal of its own.
• Upon receiving the adjacent terminaldata request packet1300, the adjacentterminal search section240 may correspond to information of the adjacent terminal obtained by searching the adjacent terminal, or may respond to the adjacent terminal data already obtained.
• In the case of a number of adjacent terminals, the adjacentterminal search section240 may correspond to the adjacent terminal information by dividing data into a plural packet.
• FIG. 13 is a configuration diagram of the adjacent terminaldata request packet1300.
• The adjacent terminaldata request packet1300 includes an adjacent terminaldata request identifier1301, a transmissionsource terminal address1302, and a searchsource terminal address1303.
• In the adjacent terminaldata request identifier1301, an identifier is stored stating that the relevant packet is the adjacent terminal data request packet.
• In the transmissionsource terminal address1302, the transmission source terminal address of the relevant packet is stored.
• In the searchsource terminal address1303, the address of the terminal (thewireless terminal200ain the example ofFIG. 12) is stored that searches the adjacent terminal by receiving the relevant packet.
• FIG. 14 is a configuration diagram of a adjacent terminaldata response packet1400.
• The adjacent terminaldata response packet1400 includes an adjacent terminaldata response identifier1401, a searchsource terminal address1402, atransmission destination terminal1403, number of theadjacent terminal1404, and anadjacent terminal address1405.
• In the adjacent terminaldata response identifier1401, an identifier is stored stating that the relevant packet is the adjacent terminal data response packet.
• In the searchsource terminal address1402, the terminal (thewireless terminal200ain the example ofFIG. 12) address is stored that collected search results of the transmission source of the relevant packet, that is, the adjacent terminal.
• In thetransmission destination terminal1403, the terminal address is stored that transmits the transmission destination terminal of the relevant packet, that is, the adjacent terminaldata request packet1300.
• In theadjacent terminal number1404, the number of the adjacent terminals (three in the example ofFIG. 12) of the wireless terminal is stored that transmits the relevant packet.
• In theadjacent terminal address1405, the adjacent terminal (thewireless terminals200bto200din the example ofFIG. 12) address of the wireless terminal is stored that transmits the relevant packet.
• FIG. 15 is a flow chart of positioning procedure ofEmbodiment 2. In the following, each step ofFIG. 15 will be explained.
• (S1501)
• Thepositioning management terminal100 transmits the adjacent terminaldata request packet1300 to all thewireless terminals200 to obtain the adjacent terminal information on eachwireless terminal200 included in the adjacent terminaldata response packet1400.
• InEmbodiment 1, it is assumed that information of the adjacent terminal has been set in the terminalinformation storage section150 of thepositioning management terminal100 in advance prior to positioning operation. However,Embodiment 2 is different fromEmbodiment 1 in that the present step collects the adjacent terminal information.
• (S1502) to (S1505)
• The same procedure with the steps S901 to S905 described inFIG. 9 ofEmbodiment 1.
• As mentioned above, inEmbodiment 2, eachwireless terminal200 is adapted to automatically obtain the adjacent terminal address through the mutual communication.
• Therefore, after installing thewireless terminal200,position information702 of all thewireless terminals200 can be automatically calculated. Accordingly, pre-configuration can be drastically reduced necessary for obtaining positions of thewireless terminals200 installed over a wide area.
Embodiment 3
• FIG. 16 is a configuration diagram of the wireless positioning system ofEmbodiment 3.
• The wireless positioning system according toEmbodiment 3 includes mobile wireless terminals300ato300cin addition to the wireless positioning system configured inEmbodiments 1 and 2.
• Thepositioning management terminal100 according toEmbodiment 3 includes a similar configuration to thepositioning management terminal100 according toEmbodiments 1 and 2.
• The terminalinformation storage section150 of thepositioning management terminal100 according toEmbodiment 3 stores the terminal address701,position information702, and the adjacentterminal list703 regarding themobile wireless terminal300 as well in addition to information that the terminalinformation storage section150 inEmbodiments 1 and 2 stores.
• The positioningobject decision section130 of thepositioning management terminal100 according toEmbodiment 3 selects a positioning standard terminal for positioning themobile wireless terminal300 from the adjacent terminal information regarding themobile wireless terminal300 andposition information702 of thewireless terminal200 in addition to the positioningobject decision section130 inEmbodiments 1 and 2.
• The positioningprocedure management section120 of thepositioning management terminal100 according toEmbodiment 3 manages procedure for positioning themobile wireless terminal300 in addition to the positioningprocedure management section120 inEmbodiments 1. and 2.
• Since theposition calculation section140 and thecommunication section110 of thepositioning management terminal100 inEmbodiment 3 are the same as those of inEmbodiments 1 and 2, descriptions will be omitted.
• The configuration of thewireless terminal200 according toEmbodiment 3 is the same as that of thewireless terminal200 according toEmbodiments 1 and 2. Each component of thewireless terminal200 is the same.
• FIG. 17 is a function block diagram of amobile wireless terminal300.
• Themobile wireless terminal300 has the same configuration as thewireless terminal200 according toEmbodiment 3. Functions of each component are the same as those explained inEmbodiment 2.
• As mentioned above, each configuration of the wireless positioning system according toembodiment 3 is explained.
• Next, descriptions will be given to operation thereof.
• FIG. 18 is an entire operation sequence of the wireless positioning system ofEmbodiment 3. In the following, each step inFIG. 18 will be explained.
• After the operation to obtainposition information702 of all thewireless terminals200 inEmbodiments 1 and 2, an operation for calculating the position of themobile wireless terminal300 is further added to make the operations inEmbodiment 3.
• (S1800)
• Thepositioning management terminal100 performs positioning of all thewireless terminals200 by the method explained inEmbodiments 1 and 2. Next, thepositioning management terminal100 performs an operation to calculate the position of themobile wireless terminal300 explained in the following.
• (S1801)
• The positioningprocedure management section120 of thepositioning management terminal100 transmits the adjacent terminaldata request packet1300 to themobile wireless terminal300 that calculates a position via thecommunication section110 to obtain the adjacent terminal of themobile wireless terminal300. As for how to obtain the adjacent terminal, method explained inEmbodiment 2 is employed
• (S1802)
• The positioningobject decision section130 of thepositioning management terminal100 selects (N+1)wireless terminals200 whose positions are defined as a positioning standard terminal among the adjacent terminals of themobile wireless terminals300 that the terminalinformation storage section150 stores.
• When selecting the positioning standard terminal, it may be randomly selected among (N+1) ormore wireless terminals200 whose positions are defined. A combination of thewireless terminals200 having the highest evaluation may be selected using a suitable evaluation function.
• (S1803)
• The positioningprocedure management section120 of thepositioning management terminal100 generates a range-findingdata request packet500 whose range-findingobject terminal address505 is the address of the positioning standard terminal selected by the positioningobject decision section130 with themobile wireless terminal300 being the terminal to be positioned.
• Next, the positioningprocedure management section120 transmits the range-findingdata request packet500 to the mobile wireless terminalinformation storage section300 via thecommunication section110.
• Upon receiving the range-findingdata request packet500, themobile wireless terminal300 performs range-finding with thewireless terminal200 specified by the range-findingobject terminal address505 to transmit the range-findingdata response packet600 to thepositioning management terminal100.
• (S1804)
• When thepositioning management terminal100 receives the range-findingdata response packet600, theposition calculation section140 calculates the position of themobile wireless terminal300.
• As for the positioning of themobile wireless terminal300, thepositioning management terminal100 may perform positioning of positioning of eachmobile wireless terminal300 on a regular basis. Alternatively, from themobile wireless terminal300, a signal (not shown) to require positioning of the self terminal is transmitted to thepositioning management terminal100. Upon receiving the signal, thepositioning management terminal100 may perform positioning of themobile wireless terminal300.
• Further, the user may command thepositioning management terminal100 to perform positioning, and the positioning of themobile wireless terminal300 may be performed according to the command.
• As mentioned above, inEmbodiment 3, (N+1) ormore wireless terminals200 are selected as positioning standard terminals among thewireless terminals200 automatically positioned by obtaining the adjacent terminal. The distance between the positioning standard terminal and themobile wireless terminal300 is measured to position themobile wireless terminal300.
• Thereby, themobile wireless terminal300 can be positioned without installing a number of base stations over a wide area to configure positions of the base stations.
• Therefore, pre-configuration can be drastically reduced necessary for, positioning thepositioning standard terminal300.
Embodiment 4
• In the above-mentionedEmbodiments 1 to 3, a procedure for theposition calculation section140 to calculate the position of the terminal to be positioned can be as follows.
• (Position Calculation Method 1)
• Theposition calculation section140 obtains the intersection of a circle whose radius is equal to positioninformation705 between the terminal to be positioned and each positioning standard terminal as the position of the terminal to be positioned with the position of each positioning standard terminal being the center.
• (Position Calculation Method 2)
• P_i(i=1 . . . k) denotes the position of each positioning standard terminal, P_tdenotes the position of the terminal to be positioned, and d_i(i=1 . . . k) denotes the distance between each positioning standard terminal and the terminal to be positioned.
• Theposition calculation section140 calculates the position of the terminal to be positioned whose distance error becomes minimum by calculating P_tthat makes a evaluation function ε (P_t) as follows minimum, for example, using least-square method.
• $\begin{array}{cc}\varepsilon \left(p_t\right)=\sum _{i=1}^k{\left(p_i-p_t-d_k\right)}^2& \left[\mathrm{Formula}1\right]\end{array}$
Embodiment 5
• InEmbodiment 5 of the present invention, descriptions will be given to the method of evaluating measurement accuracy of the terminal to be positioned. The configuration of the wireless positioning system and each terminal is the same asEmbodiments 1 to 4.
• InEmbodiment 5, when the terminal to be positioned has (N+1) adjacent terminals whose positions are defined, the positioningobject decision section130 of thepositioning management terminal100 evaluates the combination of thewireless terminals200 to be a candidate for the positioning standard terminal according to, for example, an evaluation function as follows to select the combination of thewireless terminals200 having the highest evaluation as the positioning standard terminal.
• (Evaluation Function 1): Determinant: 1
• For example, among adjacent terminals for which (N+1) ormore position information702 has been defined, regarding a combination of thewireless terminals200 to be the positioning standard terminal, the position of the positioning standard terminal is made to be {P₀, P₁, . . . , P_N}, respectively.
• Among them, the following determinant M is made to be an evaluation function, whose element is a difference vector between {P₁, . . . , P_N} and {P₀}.
• 
  M=[p₁. . . p₀, . . . , p_N−p₀]  [Formula 2]
• The positioningobject decision section130 calculates values of the evaluation function regarding the combination of all thewireless terminals200 to be a candidate of the positioning standard terminal to select the combination having the highest value of the evaluation function as the positioning standard terminal.
• In general, when the positioning standard terminals of three points are on the same straight line in the calculation of the two-dimensional position, and when the positioning standard terminals of four points are on the same plane in the calculation of the three-dimensional position, a plurality of calculation position candidates exist and measurement accuracy is deteriorated.
• The above evaluation function denotes a dispersion degree in position relation of the positioning standard terminal.
• Thus, by selecting the combination having a higher value of the evaluation function, the positioning standard terminal having more dispersed position relation enables measurement of the position of the position of the positioning standard terminal, resulting in improvement of measurement accuracy.
• (Evaluation Function 2) Determinant: 2
• Similarly, the same effect will be obtained by making the following determinant M to be the evaluation function, whose element is a normalized difference vector between {P₁, . . . , P_N} and {P₀}.
• $\begin{array}{cc}M=\left[\frac{p_1-p_0}{p_1-p_0},\dots ,\frac{p_N-p_0}{p_N-p_0}\right]& \left[\mathrm{Formula}3\right]\end{array}$
• (Evaluation Function 3): Evaluation of Accuracy of Calculated Position: 1
• P_idenotes the position of the wireless terminal200 (suffix is made to be i) whoseposition information702 is defined. D_ijdenotes thedistance information705 with other wireless terminal200 (suffix is made to be j) whoseposition information702 is defined. The positioningobject decision section130 calculates an evaluation value g_ias follows.
• $\begin{array}{cc}{g}_t=\frac{1}{N}\sum _j^N{\left(p_t-p_j-d_{\mathrm{ij}}\right)}^2& \left[\mathrm{Formula}4\right]\end{array}$
• N is the number of the adjacent terminal whoseposition information702 has been defined anddistance information705 has been obtained among the adjacent terminals of the wireless terminal i in the terminalinformation storage section150 of thepositioning management terminal100.
• Next, among the adjacent terminals whoseposition information702 has been defined, the positioningobject decision section130 selects (N+1) terminals having a smaller evaluation value g_iin order to select as the positioning standard terminal.
• The evaluation value g_idenotes a degree of difference between a distance calculated by the position relation calculated by theposition calculation section140 anddistance information705 obtained from thedistance measurement section220. The smaller the value g_i, the more the position calculated by theposition calculation section140 corresponds with thedistance information705 obtained by the measurement of thedistance measurement section220.
• That is, the smaller the evaluation value g_i, the higher the position accuracy calculated by theposition calculation section140.
• Accordingly, by employing the combination of the positioning standard terminal having the smallest evaluation value g_i, the terminal to be positioned can be positioned with thewireless terminal200 having a high calculation position accuracy being the positioning standard terminal, resulting in improvement of positioning accuracy of the terminal to be positioned.
• (Evaluation Function 4): Evaluation of Accuracy of Calculated Position: 2
• A value denoting the accuracy of the calculated position as follows may be used as the evaluation value g_i, for example.
• $\begin{array}{cc}{g}_i=\frac{1}{N}\sum _j^N{\left(\frac{p_i-p_j-d_{\mathrm{ij}}}{d_{\mathrm{ij}}}\right)}^2\mathrm{OR}g_i=\frac{1}{N}\sum _j^N{\left(\frac{p_i-p_j-d_{\mathrm{ij}}}{p_i-p_j}\right)}^2& \left[\mathrm{Formula}5\right]\end{array}$
• In general, thedistance information705 measured by wireless includes errors. Theposition information702 calculated by thedistance information705 including errors also includes errors.
• When calculating the position of thenext wireless terminal200 using theposition information702 including errors, calculation position errors of the terminal to be positioned are supposed to grow as the procedure advances.
• Therefore, by selecting the positioning standard terminal capable of improving positioning accuracy of the terminal to be positioned like the above (evaluation function3) and (evaluation function4) to calculate positions in order, a wireless positioning system having a few position errors can be obtained.
• InEmbodiment 5, when there are a plurality of thewireless terminals200 in which (N+1) ormore position information702 of the adjacent terminals is defined, the positioningobject decision section130 may select the combination of the highest evaluation as the terminal to be positioned and the positioning standard terminal by evaluating combinations of thewireless terminals200 that could all be the positioning standard terminals of all thewireless terminals200 according to the above evaluation function.
• Thus, the combination of thewireless terminals200 having the highest positioning accuracy of the terminal to be positioned can be positioned as the positioning standard terminal, resulting in the improvement of positioning accuracy of the entire wireless positioning system.
Embodiment 6
• InEmbodiment 6 of the present invention, descriptions will be given to a method in which positioninformation702 of thewireless terminal200 is calculated as relative coordinates in place of absolute coordinates to be stored in the terminalinformation storage section150. Configurations of the wireless positioning system and each terminal is the same asEmbodiments 1 to 5.
• FIG. 19 is a sequence diagram showing procedure in which relative positions of thewireless terminal200 of (N+1) or more are obtained and stored inposition information702. Each step ofFIG. 19 will be explained as follows.
• (S1901)
• The positioningprocedure management section120 of thepositioning management terminal100 selects k (k is an integer greater than N+1) wireless terminals200 (here, k=4 and suffixes are a to d) to be adjacent terminals each other from information of the adjacent terminal that terminalinformation storage section150 stores.
• The positioningprocedure management section120 transmits the range-findingdata request packet500 including addresses of thewireless terminals200bto200das range-finding object terminal addresses505 to thewireless terminal200a.
• Upon receiving the range-findingdata request packet500, thewireless terminal200aperforms range-finding among thewireless terminals200bto200dto transmit the range-findingdata response packet600 to thepositioning management terminal100.
• (S1902) to (S1903)
• Thepositioning management terminal100 transmits the range-findingdata request packet500 including addresses of thewireless terminals200bto200dwhose distances are undefined as range-finding object terminal addresses505 to thewireless terminals200bto200dto obtainmutual distance information705 of thewireless terminals200ato200d.
• (S1904)
• Theposition calculation section140 of thepositioning management terminal100 calculates relative positions of thewireless terminals200ato200dfrom obtainedmutual distance information705.
• For example, in the case where three-dimension positions of thewireless terminals200ato200dare obtained, the position of thewireless terminal200ais made to be P₁=(0, 0, 0), that of thewireless terminal200bP₂=(x₂, 0, 0), that of thewireless terminal200cP₃=(x₃, y₃, 0), and the positions except200ato200camongk wireless terminals200 being made to be P_i=(x_i, y_i, z_i) (i=4, . . . , k, x, y, and z are unknown)
• Theposition calculation section140 can obtain relative positions of eachwireless terminal200 with the position of p1 being an origin by obtaining a position that makes a difference between a distance obtained from the calculated position and the measureddistance information705 to be minimum.
• Thus, by calculating the relative position to store it into theposition information702, thewireless terminal200 can be obtained whose (N+1) ormore position information702 have been confirmed prior to start of the position calculation operation.
• Thereby, with no configuration of the positions of (N+1) ormore wireless terminals200, the positions of all thewireless terminals200 can be obtained.
• With the method above, relative position may possibly be obtained which may be a mirror-symmetry or may be subjected entirely to rotational transfer or parallel displacement against a true position, however, a manual input by input means (not shown) may be allowable to correct the mirror-symmetry and rotation to perform correction.
• Thereby,position information702, in which mirror-symmetry and rotated position are corrected, is obtained and the position equivalent to the true position can be obtained.
• The above mentioned relative position may be calculated frommutual distance information705 of thewireless terminal200 by determining only signs of unknown variables of the above-mentioned P₂=(x₂, 0, 0) and P₃=(x₃, y₃, 0) in advance to install such that the position relation in the predeterminedk wireless terminals200 should have predetermined signs.
• Thereby, the position equivalent to the true position can be obtained with neither mirror-symmetry nor rotation of the whole by the installation with only signs of the position relation being matched with coordinates for calculating the position.
Embodiment 7
• InEmbodiment 7 of the present invention, descriptions will be given to a method of recalculating thecalculated position information702 after positioning to correct and improve accuracy. The configuration of the wireless positioning system and each terminal is the same asEmbodiments 1 to 6.
• (Recalculation Method 1)
• Theposition calculation section140 of thepositioning management terminal100 refers again to thedistance information705 and theposition information702 that the terminalinformation storage section150 stores after the completion of the positioning to recalculate the position of eachwireless terminal200.
• When theposition calculation section140 recalculates position information, since muchmore distance information705 is stored in the terminalinformation storage section150 compared with the above-mentioned step in the middle of the positioning operation, positioning accuracy can be further improved using thedistance information705.
• (Recalculation Method 2)
• After all the positioning procedures are completed and positioning is concluded, theposition calculation section140 of thepositioning management terminal100 transmits the range-findingdata request packet500 regarding part of or all thedistance information705 amongundefined distance information705 to correctposition information702 upon increasing the number of data ofdistance information705.
• Through this method, by increasing the number of data ofdistance information705, accuracy can be more precisely improved.
• Regarding the adjacent terminal whosedistance information705 is undefined, the above-mentioned evaluation value g_iis calculated andonly distance information705 of the adjacent terminal whose evaluation value g_iis smaller than a predetermined threshold value (=position information is high) is added, and theundefined distance information705 is obtained.
• By additionally obtainingdistance information705 of the adjacent terminal having a smaller evaluation value g_iand calculating the position usingdistance information705,distance information705 of thewireless terminal200 whose position is more precisely measured can be used, resulting in the improvement of positioning accuracy of thewireless terminal200.
• (Recalculation Method 3)
• Regarding the combination of (N+1) ormore wireless terminals200, theposition calculation section140 of thepositioning management terminal100 calculates the number of thewireless terminals200 to be an adjacent terminal in common from eachwireless terminals200 included in the combination for each combination after all the positioning procedures are completed and positioning is concluded.
• Next, the combination having the maximum number is selected as the positioning standard terminal. Thewireless terminal200 for which the combination becomes the adjacent terminal in common is selected as the terminal to be positioned respectively. Then, the position of each terminal to be positioned is calculated.
• Thus, the position of the terminal to be positioned is calculated based on theposition information702 of the common positioning standard terminal, allowing to prevent the above-mentioned problem of propagation of position errors.
Embodiment 8
• The evaluation value g_ishowing calculation position accuracy explained inEmbodiment 5 may be output and presented to other wireless terminals via wireless or wired interfaces as an index of accuracy ofposition information702. (not shown)
• By presenting the index of accuracy ofposition information702 along withposition information702, the system utilizing theposition information702 obtained form the present wireless positioning system becomes possible to use theposition information702 added with calculation position accuracy.
• The evaluation value g_ishowing accuracy may be displayed on the screen (not shown) operated by workers along withposition information702. Specifically, it is conceivable that display means such as a liquid crystal display and a light emitting diode is provided on thepositioning management terminal100, for example, and an accuracy index value is displayed thereon.
Embodiment 9
• As explained inEmbodiment 3, when themobile wireless terminal300 exists in the wireless positioning system, themobile wireless terminal300 may be actually fixedly installed in the wireless positioning system instead of being mobile.
• The fixedwireless terminal200 additionally installed to the wireless positioning system may be handled as themobile wireless terminal300.
• Even thewireless terminal200 is additionally installed, by calculating position as themobile wireless terminal300, the addedwireless terminal200 searches the adjacent terminal and selects the position standard terminal having higher position calculation accuracy to perform range-finding only with the position standard terminal.
• Therefore, the position of the addedwireless terminal200 can be automatically obtained and communication amount for range-finding can be reduced.
• InEmbodiment 3, themobile wireless terminal300 and thewireless terminal200 are configured as the different terminal, however, they may be treated as thesame wireless terminal200.
• In this case, a sign that discriminates whether thewireless terminal200 is themobile wireless terminal300 or not is stored in the terminalinformation storage section150 of thepositioning management terminal100. The positioningprocedure management section120 positions eachwireless terminal200 andmobile wireless terminal300 according to the sign.
• The sign for the above discrimination may be switched during the system operation.
• For example, positioning may be performed under a initially installed condition that all the terminals are thewireless terminal200. Thereafter part of thewireless terminal200 is switched for themobile wireless terminal300, and positioning may be performed for the relevantmobile wireless terminal300 as needed according to the method explained inEmbodiment 3.
• Thus, a positioning method becomes possible in which positioning is performed including, for example, the fixed andimmobile wireless terminal200 and themobile wireless terminal300 that does not move at the time of positioning of eachwireless terminal200 and moves thereafter, and then only themobile wireless terminal300 is positioned in repetition.
• Positioning of much morewireless terminals200 increases candidates of the available positioning standard terminal, therefore, high precision positioning can be performed using more accurate positioning standard terminal and by correcting by the distance of the positioning standard terminal of higher position calculation accuracy after the positioning.
• In the case where after eachwireless terminal200 is once installed, installation position of only part of thewireless terminal200 is moved, the position can be re-measured with smaller communication amount by temporarily handling thewireless terminal200 as themobile wireless terminal300.
Embodiment 10
• InEmbodiments 1 to 9 the above, the number of the positioning standard terminal selected by the positioningobject decision section130 is made to be (N+1), however, it is possible to select more than (N+1) positioning standard terminals to calculate the position of the terminal to be positioned from the distance from more than (N+1) positioning standard terminals.
• Position calculation bydistance information705 from much more positioning standard terminals improves the positioning accuracy of the terminal to be positioned.
• The evaluation value g_ishowing the above-mentioned position calculation accuracy may be utilized to select an appropriate number of the positioning standard terminals among more than (N+1) positioning standard terminals.
• For example, thewireless terminal200 whose evaluation value g_iis smaller than a predetermined threshold value may be selected as the positioning standard terminal.
• Thus, such a selection of the positioning standard terminal enables selection of a number ofwireless terminals200 having high position calculation accuracy alone as the positioning standard terminal, resulting in improvement of positioning accuracy of the terminal to be positioned.
Embodiment 11
• In Embodiment 11 of the present invention, descriptions will be given to an operation example where the number of the adjacent terminals whose position known is poor and the number of positioning standard terminals is scarce. The configuration of the wireless positioning system and each terminal is the same asEmbodiments 1 to 10.
• The positioningobject decision section130 reduces the dimension to select N positioning standard terminals when the number of the adjacent terminals is less than (N+1) for all the position-undefined wireless terminals200 andmobile wireless terminals300.
• The positioningprocedure management section120 performs range-finding of the positioning standard terminal and the terminal to be positioned to calculate the position of the terminal to be positioned in the (N−1)-th dimension space determined by the positions of the N positioning standard terminals selected by the positioningobject decision section130.
• The calculation is allowable by reducing the dimension from (N−1). The position may be calculated using restriction information such that the terminal is installed on the floor face or the ceiling face, for example.
• Thus, in the case where the number of the adjacent terminals is less than (N+1), the position of thewireless terminals200 and themobile wireless terminals300 can be defined in the part where thewireless terminals200 are sparsely arranged by calculating the position with a reduced dimension.
Embodiment 12
• In the above-mentionedEmbodiments 1 to 11, the position is adapted to be calculated by distance information of the position-knownwireless terminal200. However, besides the distance, by measuring the time difference of arrival of the radio waves transmitted from the terminal to be positioned at each positioning standard terminal, it is possible to calculate the position of the terminal to be positioned as an intersection point of the hyperbolic line with the position of each positioning standard terminal and measured radio wave propagation time difference being parameters.
• Evidently, the same effect can be obtained by deciding the positioning standard terminal and the terminal to be positioned by the present invention in succession regardless of a positioning method to calculate the position of the terminal to be positioned.
Embodiment 13
• In the above-mentionedEmbodiments 1 to 12, thepositioning management terminal100 may include thedistance measurement section220 and the range-findingdata processing section230, and the above-mentioned positioning procedure may be followed with thepositioning management terminal100 itself being subjected to positioning.
• Similarly, thepositioning management terminal100 may further include the adjacentterminal search section240 and the adjacent terminaldata processing section250 and to perform positioning as thewireless terminal200 or themobile wireless terminal300 explained inEmbodiments 2 and 3.
• Thereby, automated position calculation becomes possible including thepositioning management terminal100.
Embodiment 14
• In the above-mentionedEmbodiments 1 to 13,distance measurement section220 calculates the distance between thewireless terminals200 based on the radio wave propagation delay time, however, other distance measurement methods such as radio wave reception strength may be utilized.
Embodiment 15
• FIG. 20 is a configuration diagram of an environment measurement system of Embodiment 15.
• The environment measurement system according to Embodiment 15 is a system that measures environmental conditions of a measurement object space, including a fixedsensor terminal2100 and amobile sensor terminal2200.
• The fixedsensor terminals2100 as fixedly installed in the measurement object space in plural to measure environmental conditions neighboring the self-terminal.
• Themobile sensor terminal2200 measures environmental conditions neighboring the self-terminal while moving in the measurement object space. Measurement points whose environmental conditions themobile sensor terminal2200 measures are supposed to be preconfigured.
• FIG. 21 is a functional block diagram of a fixed sensor terminal101.
• The fixedsensor terminal2100 includes aterminal control section2110, awireless communication section2111, and anenvironment measurement section2112.
• Theterminal control section2110 obtains measurement values of environmental conditions measured by theenvironment measurement section2112 and exchanges data with other sensor terminals via thewireless communication section2111.
• Thewireless communication section2111 performs wireless communication with other sensor terminals.
• Theenvironment measurement section2112 includes one or a plurality of sensors such as a temperature sensor, a humidity sensor, and an illuminance sensor to measure environmental conditions neighboring the self-terminal such as temperature, humidity, and illuminance.
• Kinds of sensors are not limited to the temperature sensor, the humidity sensor, and the illuminance sensor but an arbitrary sensor can be used according to the environment conditions in need of measurement. For example, a sensor may be used that detects a particular chemical substance.
• FIG. 22 is a functional block diagram of amobile sensor terminal2200.
• Themobile sensor terminal2200 includes aterminal control section2210, awireless communication section2211, anenvironment measurement section2212, awireless positioning section2213, a selfposition control section2214, and adrive section2215.
• Theterminal control section2210 obtains measurement values measured by theenvironment measurement section2212, and exchanges data with other sensor terminals through thewireless communication section2211.
• Theterminal control section2210 has a role to control the position of the self-terminal, in addition. For example, theterminal control section2210 makes themobile sensor terminal2200 move to a desired position by the function of the selfposition control section2214, or detects to manage the position of themobile sensor terminal2200 by the function of thewireless positioning section2213.
• Thewireless communication section2211 performs wireless communication with other sensor terminals.
• The configuration and functions of theenvironment measurement section2212 are the same as those of theenvironment measurement section2112.
• The wireless positioning section2113 detects the position of themobile sensor terminal2200 using wireless communication. Method of detection will be mentioned later.
• The selfposition control section2214 controls the position of themobile sensor terminal2200 to be a desired position by properly operating thedrive section2215 from a target position and the current position of themobile sensor terminal2200.
• As for a method of controlling the sensor terminal to be the desired position, such a method is conceivable that to calculate a deviation between the target position and the current position of themobile sensor terminal2200 to change operation time of thedrive section2215 based on the deviation, and to give an output command in proportion to the deviation to thedrive section2215.
• Thedrive section2215 is means to move themobile sensor terminal2200. Thedrive section2215 includes a motor and wheels, for example, being capable of moving themobile sensor terminal2200 by rotating wheels. Thedrive section2215 may be configured so that a walk form by a caterpillar and link mechanism move themobile sensor terminal2200 as well.
• Theterminal control section2110, theterminal control section2210, thewireless positioning section2213, and the selfposition control section2214 may be configured using hardware such as a circuit device that achieves these functions or may be configured using operation devices such as a microprocessor and a CPU (Central Processing Unit) and software specifying their operations.
• Thewireless communication section2111 and thewireless communication section2211 appropriately include a necessary configuration such as a wireless communication interface.
• In the above, the configuration of the environment measurement system according to Embodiment 15 is explained.
• Next, descriptions will be given to a position detection method by thewireless positioning section2213.
• FIG. 23 is a diagram illustrating procedure for awireless positioning section2213 to calculate the distance between themobile sensor terminal2200 and a fixedsensor terminal2100. Each step ofFIG. 23 will be explained as follows.
• (S401)
• Themobile sensor terminal2200 transmits a range-finding request signal via thewireless communication section2211.
• (S402)
• Upon receiving the range-finding request signal, the fixedsensor terminal2100 transmits a range-finding response signal to themobile sensor terminal2200.
• (S403)
• Themobile sensor terminal2200 receives the range-finding response signal via thewireless communication section2211. Thewireless positioning section2213 measures the response time from the transmission of the range-finding request signal to the reception of the range-finding response signal.
• Thewireless positioning section2213 can measure the response time by such a method as to start time measurement by a counter at the time of transmitting the range-finding request signal and to read a time measurement value by the counter at the time of receiving the range-finding response.
• (S404)
• Thewireless positioning section2213 of themobile sensor terminal2200 calculates the distance between themobile sensor terminal2200 and the fixedsensor terminal2100 by multiplying the response time measured in step S403 by the velocity of the electromagnetic wave and by referring to a correspondence table between a predetermined response time and the distance.
• FIG. 24 is a diagram illustrating a method for thewireless positioning section2213 to calculate the position of themobile sensor terminal2200.
• Thewireless positioning section2213 performs procedure to calculate the distance between themobile sensor terminal2200 and the fixedsensor terminal2100 for a plurality of fixed sensor terminals2100 (for example,100ato100cinFIG. 24).
• Next, thewireless positioning section2213 obtains a circle whose center is the fixedsensor terminal2100 and whose radius is calculated distance between terminals from the inter-terminal distances between a plurality of fixedsensor terminals2100 and themobile sensor terminal2200 and positions of each fixed sensor terminals2100 (assumed to be known).
• Thewireless positioning section2213 can detect the area where these circles intersect as the position of themobile sensor terminal2200.
• Therefore, in order to detect the position of themobile sensor terminal2200 with high precision, it is preferable to calculate the inter-terminal distance among three or morefixed sensor terminals2100.
• In the above, a method of detecting the position, of themobile sensor terminal2200 is explained.
• Next, descriptions will be given to operation of themobile sensor terminal2200 to measure environmental conditions.
• FIG. 25 is an operation flow when themobile sensor terminal2200 measures environmental conditions.
• Each step ofFIG. 25 will be explained as follows.
• (S601)
• Theterminal control section2210 decides a measurement point where the environmental conditions are measured next in the preset measurement point list. Theterminal control section2210 may select the measurement point according to a preset order, or select the nearest measurement point from the current position of themobile sensor terminal2200. The next measurement point may be selected by other methods.
• (S602)
• Thewireless positioning section2213 detects the position of themobile sensor terminal2200 by the methods explained inFIGS. 23 and 24.
• (S603)
• The selfposition control section2214 performs control operation to move themobile sensor terminal2200 to a specified measurement point with the measurement point decided in step S601 being a target position and with the position detected in step S602 being the current position.
• The selfposition control section2214 decides operation time of thedrive section2215 from the deviation between the target position and the current position, for example, to move themobile sensor terminal2200 to the measurement point by making thedrive section2215 operate for the operation time.
• Alternatively, the selfposition control section2214 may move themobile sensor terminal2200 to the measurement point by detecting and moving the current position by thewireless positioning section2213 in repetition until the deviation between the position of the measurement point and the current point becomes a predetermined threshold or less.
• As for the method of controlling the position of themobile sensor terminal2200, a method of controlling a general self-propelled robot may be applied.
• (S604)
• When themobile sensor terminal2200 moves to the measurement point, theenvironment measurement section2212 measures environmental conditions neighboring the self-terminal.
• (S605)
• Theterminal control section2210 judges whether measurement of environmental conditions is completed or not for all measurement points included in the measurement point list. When there is an uncompleted measurement point, return to step S601 to repeat the same processing. After the completion of the measurement in all the measurement points included in the measurement point list, the measurement of environmental conditions is completed.
• In the above, an operation of measuring environmental conditions of themobile sensor terminal2200 is explained.
• The fixedsensor terminal2100 may measure environmental conditions neighboring the self-terminal in synchronization with themobile sensor terminal2200, or measure environmental conditions independent of themobile sensor terminal2200.
• As mentioned above, according to Embodiment 15, since small number of the fixedsensor terminals2100 andmobile sensor terminals2200 are adapted to measure environmental conditions of the measurement object space, it is possible to measure environmental conditions at many measurement points without increasing sensors to be fixedly installed.
• According to Embodiment 15, thewireless positioning section2213 detects the current position of themobile sensor terminal2200 utilizing the wireless communication signal between the fixedsensor terminal2100 and themobile sensor terminal2200. Themobile sensor terminal2200 measures environmental conditions utilizing the detection results to understand the position of the self-terminal.
• Thereby, with no need of installing other devices to be a reference of the current position of themobile sensor terminal2200 such as a guide rail and a marker, an environment measurement system can be introduced with less cost with ease.
• In general, the position after a self-propelled robot moved has an error against a target position.
• In Embodiment 15, since the position of themobile sensor terminal2200 is detected by wireless, an actually measured point can be correctly grasped by holding both the measured environment conditions and the detection point of themobile sensor terminal2200 even when errors exist from the measurement point.
• That is, measurement of environment conditions at a position other than a predetermined measurement point results in a correct measurement of environment conditions of the measurement object area because the correspondence relation itself is not erroneous between the position and the environment conditions.
• By performing feedback of the detected position to make it move to the measurement point, themobile sensor terminal2200 can be correctly moved to the measurement point.
Embodiment 16
• FIG. 26 is a configuration diagram of an environment measurement system of Embodiment 16.
• In Embodiment 16, the fixedsensor terminal2100 is installed at a position where measurement of environmental conditions is required for a larger time period than other measurement points. Themobile sensor terminal2200 measures environmental conditions at the measurement position where no larger time period is required other than that.
• For example, in an environment measurement system that measures the temperature inside a building, heat movement near awindow2701 and agateway2702 is large, requiring measurement of environmental conditions with a large time period. To the contrary, in the floor portion other than that, no measurement with a large time period is required.
• Accordingly, as shown inFIG. 26, the fixedsensor terminal2100 is installed at a position neighboring thewindow2701 or near thegateway2702 where a large time period is required. Themobile sensor terminal2200 measures environmental conditions while moving at measurement points besides those.
• Even when the fixedsensor terminal2100 and themobile sensor terminal2200 measure environmental conditions in synchronization, while the fixedsensor terminal2100 continuously measures environmental conditions of the same place, themobile sensor terminal2200 measures environmental conditions of a plurality of measurement points while moving.
• As a result, the fixedsensor terminal2100 more frequently performs measurement of the same measurement point.
• As mentioned above, in Embodiment 16, the fixedsensor terminal2100 is installed at a position where measurement is required for a larger time period than other measurement points. Themobile sensor terminal2200 measures environmental conditions at a position where no larger time period is required.
• Thus, the fixed sensor terminal needs not to be installed at all positions, enabling an effective measurement of environmental conditions with fewer number of terminals. Further, a flexible system can be configured according to demands of the system.
Embodiment 17
• FIG. 27 is a configuration diagram of an environment measurement system of Embodiment 17.
• The environmental measurement system according to Embodiment 17 includes four or moremobile sensor terminals2200. The configuration of themobile sensor terminal2200 is the same as Embodiments 15 and 16.
• FIG. 28 is a diagram illustrating a state in which themobile sensor terminal2200 switches a role of a self terminal.
• In Embodiment 17, themobile sensor terminals2200 detect the position each other to measure environmental conditions while switching two roles: a role to be an object for moving and position detection to move to the measurement point and the role to designate a standard position for position detection without moving.
• Hereinafter, themobile sensor terminal2200 to play the former role is referred to as a positiondetection object terminal2902, and themobile sensor terminal2200 to play the latter role is referred to as a positiondetection standard terminal2901. The measurement point list for measuring environmental conditions and the initial position of eachmobile sensor terminal2200 is assumed to be set in advance.
• FIG. 29 is an operation flow for the positiondetection object terminal2902 to measure environmental conditions.
• Descriptions will be given to each step inFIG. 29.
• (S1001)
• The present step is the same as the step S601 inFIG. 25.
• (S1002)
• Theterminal control section2210 decides the positiondetection object terminal2902 and positiondetection standard terminal2901 other than the same among eachmobile sensor terminal2200 based on the position of the measurement point decided in step S1001. Hereinafter the positiondetection object terminal2902 measures environmental conditions of the measurement point decided in step S1001.
• Theterminal control section2210 makes the farthestmobile sensor terminal2200 from the measurement point decided in step S1001 the positiondetection object terminal2902, for example, and makes othermobile sensor terminals2902 the positiondetection standard terminals2901.
• (S1003)
• Thewireless positioning section2213 detects the position of the positiondetection object terminal2902. Position detection can be performed by transmitting and receiving a range-finding signal between the positiondetection object terminal2902 and the position detection standard terminal2901 like the position detection by thewireless positioning section2213 in Embodiments 15 and 16.
• (S1004)
• The positiondetection object terminal2902 moves to the measurement point that the selfposition control section2214 designates according to the same procedure as step S603 inFIG. 25.
• (S1005)
• The same as step S604 inFIG. 25.
• (S1006)
• The same as step S605 inFIG. 25.
• As mentioned above, the environment measurement system according to Embodiment 17 includes four or moremobile sensor terminals2200. Themobile sensor terminals2200 measure environmental conditions of the measurement object space by detecting the position each other to move while switching two roles of the positiondetection object terminal2902 and the positiondetection standard terminal2901.
• Thereby, with fewer terminals, environmental conditions at a number of measurement points can be measured.
• According to the environment measurement system according to Embodiment 17, only by setting the initialmobile sensor terminal2200, environmental conditions of the building and the factory can be measured including position information. Thus, setting work for starting environmental measurement can be drastically reduced.
• The environment measurement system according to Embodiment 17 is constituted only by the moremobile sensor terminals2200. However, the position of the positiondetection object terminal2902 may be detected by making a configuration including one or two fixedsensor terminals2100 to transmit and receive a range-finding signal between the positiondetection object terminal2902 and the fixedsensor terminal2100.
• Thereby, position detection precision of the positiondetection object terminal2902 can be improved.
• It is explained that in Embodiment 17, there are four or moremobile sensor terminals2200. However, if coarse precision is allowable for position detection of themobile sensor terminal2200, the same method can be used as that explained in Embodiment 17 even when themobile sensor terminal2200 is three or less.
Embodiment 18
• In Embodiment 18, an example will be explained in which a decision method of the measurement point is changed in step S1001 of Embodiment 17. In Embodiment 18, such operations are performed as follows in step S1001.
• (S1001)
• Theterminal control section2210 calculates a distance between a position of the measurement point where measurement of environmental conditions has not been completed among the preset measurement point list and a current position of eachmobile sensor terminal2200.
• Next, theterminal control section2210 makes a measurement point in which at least three or more distances out of calculated distances are smaller than a predetermined value to be the following measurement point. The predetermined value is a communicable distance of thewireless communication section2211, for example.
• A decision of the next measurement point can prevent such an event that the positiondetection object terminal2902 moves beyond a communicable distance with the position detection standard terminal2901 to cause a failure in position detection.
• When there is a plurality of measurement points that satisfies the above condition, a gravity center position of the current position of eachmobile sensor terminal2200 is calculated. Then, the next measurement point may be decided as the nearest measurement point to the gravity center point among a plurality of measurement points that satisfies the above condition.
• Thereby, environmental conditions can be measured from the point near themobile sensor terminal2200, making it possible to reduce the time for measuring a moving distance and environmental conditions.
Embodiment 19
• In Embodiment 19, an example will be explained in which a method of deciding the positiondetection object terminal2902 and the positiondetection standard terminal2901 is changed in step S1002 of Embodiment 17. In Embodiment 19, such operations are performed as follows in step S1002.
• (S1002: 1)
• Theterminal control section2210 calculates a distance between a position of the measurement point where measurement of environmental conditions has not been completed among the preset measurement point list and a current position of eachmobile sensor terminal2200.
• Next, theterminal control section2210 selects three or moremobile sensor terminals2200 whose calculated distance is smaller than a predetermined value to make these the positiondetection standard terminal2901. Othermobile sensor terminals2200 are made to be positiondetection object terminals2902.
• (S1002: 2)
• When there is a plurality of candidates of combination of the positiondetection standard terminals2901, theterminal control section2210 may make a combination having a high position detection precision in a geometric relation with each measurement point to be the positiondetection standard terminal2901, and othermobile sensor terminals2200 to be the positiondetection object terminals2902.
• For an evaluation index of selecting a combination having high position detection precision, GIDOP (Geometric Dilution of Precision) can be utilized that is used in the field of GPS (Global Positioning System).
• Thereby, position detection precision of the positiondetection object terminal2902 improves, achieving reduction in position errors regarding the measurement point where environmental conditions are measured.
• An evaluation function may be defined by combining a method of deciding the measurement point described in Embodiment 18 and the method of deciding the positiondetection object terminal2902 and the position detection standard terminal2901 in Embodiment 19.
• Theterminal control section2210 selects a measurement point having the highest evaluation value of the evaluation function, the positiondetection object terminal2902, and the positiondetection standard terminal2901.
• In this case, it is possible to integrally evaluate the position of the measurement point and the combination of the positiondetection object terminal2902 and the position detection standard terminal2901 to improve the position detection precision, as well.
Embodiment 20
• In Embodiments 15 to 19 in the above, a measurement point list for measuring environmental conditions is assumed to be preset. In Embodiment 20, an operation example will be explained in which the measurement point list is automatically generated.
• Embodiment 20 is constituted by the fixedsensor terminal2100 and themobile sensor terminal2200 like Embodiments 15 to 19. Configuration of each terminal is the same as that of Embodiments 15 to 19.
• FIG. 30 is a diagram showing the state in which a measurement object space is divided.
• In Embodiment 20, the measurement object space is divided into a lattice shape of a predetermined interval. The measurement point list is constituted bytypical points3101 of the area (cell) sectioned by each lattice. Thetypical point3101 is the center of each cell for example.
• By making thetypical point3101 of each cell to be the measurement point, there is no need to configure the measurement point list separately, making the preset work for starting measurement of environmental conditions to be simpler.
• Among cells partitioned in a lattice shape, thetypical point3101 of the cell excluding the cell where the fixedsensor terminal2100 is installed may be the measurement point. Thereby, an overlapping of the measurement point can be prevented, enabling an efficient measurement of environmental conditions.
• In the step for deciding the next measurement point (step S601 or S1001) in Embodiments 15 to 19, a predetermined interval between measurement points may be defined instead of selecting the next measurement point from a preset measurement point list.
• In that case, theterminal control section2210 calculates the position that is displaced by a predetermined interval from the measurement point measured in the previous step.
• Thus, the same effect as Embodiment 20 is exhibited by sequentially calculating the next measurement point instead of presetting the measurement point list.
• In the step (S601 or S1001) for deciding the next measurement point in Embodiments 15 to 19, the next measurement point may be defined by deciding a random movement direction and movement amount by pseudorandom numbers generation and the like to follow the movement direction and movement amount.
• In this case, by a random measurement while detecting the position of themobile sensor terminal2200 by mobile communication, it is possible to autonomously minutely measure the entire measurement object space in place of pre-configuring the measurement point list.
Embodiment 21
• In Embodiment 21, a configuration example of themobile sensor terminal2200 will be explained. Other configurations are the same as Embodiments 15 to 20.
• FIG. 31 is a configuration diagram of themobile sensor terminal2200 of Embodiment 21.
• Themobile sensor terminal2200 according to Embodiment 21 includes amobile cart3201, acontrol module3202, a support table3203, and asensor module3204.
• Themobile cart3201 includes means for moving on a two-dimension plane, for example, a wheel.
• The terminal,control section2210 and thewireless communication section2211 are built-in in thecontrol module3202.
• The support table3203 is a bar-shaped pedestal vertically installed to themobile cart3201.
• Thesensor module3204 accommodates theenvironment measurement section2212 and one or a plurality of the same is installed along the support table3203.
• By configuring themobile sensor terminal2200 like the above, it becomes possible to measure environmental conditions in the height direction simultaneously, allowing more detailed measurement of environmental conditions.
• In the same way, as for the fixedsensor terminal2100, a bar-shaped support table may be provided and a plurality of sensor modules may be installed on the support table. Thereby, more detailed measurement of environmental conditions becomes possible for the installation location of the fixedsensor terminal2100.
Embodiment 22
• FIG. 32 is a configuration diagram of a facility management system of Embodiment 22.
• The facility management system according to Embodiment 22 includes afacility management apparatus3300 in addition to the environment measurement system according to Embodiments 15 to 21.
• Thefacility management apparatus3300 includes afacility management section3301 and awireless communication section3302.
• In Embodiment 22, thefacility management apparatus3300 obtains measurement data measured by the environment measurement system through thewireless communication section3302. Thefacility management section3301 controls facility equipment such as air-conditioning and lighting based on the measurement data.
• As mentioned above, according to Embodiment 22, fewer sensor terminals measure a lot of environmental conditions, allowing control of facility equipment based on measurement results.
• Thereby, facility equipment can be controlled more minutely such that temperature and lighting are adjusted to suite personal tastes and facility equipment is controlled with high energy-saving effect according to a fine temperature distribution in the space.
Embodiment 23
• In the above Embodiments 15 to 22, the fixedsensor terminal2100 and themobile sensor terminal2200 can use an ultra wideband impulse wireless signal that transmits an impulse signal at the time of transmitting the range-finding request signal and the range-finding response signal.
• Thereby, the response time can be accurately measured, allowing to detect an inter-terminal distance and a terminal position more accurately.
• In the above Embodiments 15 to 22, the inter-terminal distance and the terminal position may be calculated based on a received radio wave intensity of the wireless communication between themobile sensor terminal2200 and the fixedsensor terminal2100.
• Alternatively, in the above Embodiments 15 to 22, the inter-terminal distance and the terminal position may be detected utilizing a time difference of reception of the transmitted range-finding request signal from themobile sensor terminal2200 by each of a plurality of the fixedsensor terminals2100, that is, a radio wave transmission time difference.
• In the above Embodiments 15 to 22, the position of the fixedsensor terminals2100 is supposed to be preconfigured, however, the relative position of the fixedsensor terminals2100 may be calculated. For example, procedures as follows may be used.
• Firstly, the distance between the fixedsensor terminals2100 is calculated based on wireless communication with the same method as the above. The position of the fixedsensor terminals2100 is detected by obtaining the relative position between the fixedsensor terminals2100. Based on the position, the position of themobile sensor terminal2200 can be detected.
• In the above Embodiments 15 to 22, the position of themobile sensor terminal2200 can be detected by installing a plurality of themobile sensor terminals2200 to utilize the range-finding signal between eachmobile sensor terminal2200 and the fixedsensor terminals2100 as well.
Embodiment 24
• In the above Embodiments 15 to 23, it is configured that thewireless positioning section2213 is included in themobile sensor terminal2200 to detect the position thereof, however, the present invention is not limited to the above configuration.
• For example, in place of themobile sensor terminal2200, any of the fixedsensor terminals2100 can include thewireless positioning section2213.
• In this case, information such as a received radio wave intensity, a radio wave propagation time, and a radio wave propagation time difference is transmitted from themobile sensor terminal2200 to the fixedsensor terminal2100. Thewireless positioning section2213 of the fixedsensor terminal2100 detects the position of themobile sensor terminal2200 based on the information.
• Alternatively, in the above Embodiments 15 to 23, the fixedsensor terminal2100 may measure the received radio wave intensity, the radio wave propagation time, and the radio wave propagation time difference by the wireless communication with themobile sensor terminal2200.
• The fixedsensor terminal2100 transmits the measurement values to other terminals having thewireless positioning section2213. Thewireless positioning section2213 of the terminal that received the information detects the position of themobile sensor terminal2200.
• In the above Embodiments 15 to 23, a central management apparatus (not shown) and the like having a wireless communication section may include the same function apart from the fixedsensor terminal2100 and themobile sensor terminal2200, for example.
• In this case, the central management apparatus and the like may be adapted to detect the position of themobile sensor terminal2200 or to transmit the measurement point whose environmental conditions to be measured next to themobile terminal2200.

Claims (33)

1. A wireless terminal positioning system including one or a plurality of wireless terminals and a positioning management terminal that manages positioning of said wireless terminal, wherein

said positioning management terminal includes:

a positioning object decision section that selects a terminal to be positioned which is a positioning object and a positioning standard terminal whose position is known from among said wireless terminals;

a positioning management section that requires distance information between said terminal to be positioned and said positioning standard terminal;

a position calculation section that calculates the position of said terminal to be positioned; and

a storage section that keeps an adjacent terminal list that wireless signals of said wireless terminal reach,

said wireless terminal includes

a distance measurement section that measures the distance from an adjacent terminal that wireless signals of said wireless terminal reach and

a communication section that transmits measurement results of said distance measurement section to said positioning management terminal; and wherein

said positioning management section requires distance information from said positioning standard terminal selected by said positioning object decision section to said terminal to be positioned selected by said positioning object decision section, and

said position calculation section calculates the position of said terminal to be positioned using the distance information and position information of said positioning standard terminal.

2. The wireless terminal positioning system ofclaim 1, wherein

said positioning object decision section repeatedly selects said terminal to be positioned and said positioning standard terminal until said position calculation section calculates positions of all said wireless terminals, and

said positioning management section requires distance information between said terminal to be positioned and said positioning standard terminal for each repetition.

3. The wireless terminal positioning system ofclaim 1, wherein

when said position calculation section calculates N-dimension coordinates of said terminal to be positioned,

said positioning object decision section selects said wireless terminal having at least N+1 said adjacent terminals whose positions are known as said terminal to be positioned, and

selects at least said N+1 said adjacent terminals as said positioning standard terminals.

4. The wireless terminal positioning system ofclaim 1, wherein

said wireless terminal includes an adjacent terminal search section that searches the adjacent terminal that wireless signals reach,

said positioning management terminal requires an adjacent terminal list of the wireless terminal to said wireless terminal,

said adjacent terminal search section searches the adjacent terminal of the relevant wireless terminal based on the request to transmit the resultant adjacent terminal list to said positioning management terminal, and

said positioning management terminal stores the adjacent terminal list in said storage section.

5. The wireless terminal positioning system ofclaim 4, wherein

said positioning management section requires an adjacent terminal list of the wireless terminal to said wireless terminal,

said positioning object decision section selects said positioning standard terminal among wireless terminals contained in the adjacent terminal list.

6. The wireless terminal positioning system ofclaim 1, wherein

said storage section stores position information of said wireless terminal and distance information from said wireless terminal to said adjacent terminal, and

said positioning object decision section calculates a precision index value of said position information based on said position information and said distance information.

7. The wireless terminal positioning system ofclaim 6, wherein

said positioning object decision section calculates a distance between a position shown by position information of said wireless terminal and a position shown by position information of said adjacent terminal of the wireless terminal based on each position information, and

obtains distance information from the wireless terminal to said adjacent terminal from said storage section to calculate a precision index value of said position information based on a difference of the both.

8. The wireless terminal positioning system ofclaim 6, wherein

said positioning object decision section selects said terminal to be positioned or said positioning standard terminal so that the precision index value of said position information becomes the highest.

9. The wireless terminal positioning system ofclaim 1, wherein

said positioning management section requires distance information between the wireless terminal and the adjacent terminal to said wireless terminal,

said position calculation section calculates a relative position of the relevant wireless terminal using the distance information.

10. The wireless terminal positioning system ofclaim 1, wherein,

after said position calculation section calculates positions of all said wireless terminals, said positioning management section requires distance information from other wireless terminals to any of said wireless terminals, and

said position calculation section re-calculates positions of said wireless terminals using the distance information.

11. The wireless terminal positioning system ofclaim 1, wherein

said positioning management terminal includes a second distance positioning section that measures the distance from an adjacent terminal that wireless signals of the relevant positioning management terminal reaches, and

said position calculation section calculates the position of the relevant positioning management terminal using distance information measured by said second distance measurement section and position information of said positioning standard terminal.

12. The wireless terminal positioning system ofclaim 1, wherein

said positioning management terminal includes a second adjacent terminal search section that searches the adjacent terminal that wireless signals reach, and

said second adjacent terminal search section stores the adjacent terminal list obtained by searching to said storage section.

13. The wireless terminal positioning system ofclaim 1, wherein

said distance measurement section measures the distance between said wireless terminals using a radio wave propagation time of the wireless signal.

14. The wireless terminal positioning system ofclaim 13, wherein

said communication section uses an ultra wideband signal that transmits an impulse signal for the wireless signal in use when said distance measurement section measures the distance between said wireless terminals.

15. The wireless terminal positioning system ofclaim 1, wherein

said communication section performs multi-hop communication.

16-20. (canceled)

21. An environment measurement system that measures environmental conditions of a measurement object space, comprising:

a fixed sensor terminal fixedly installed in said measurement object space;

a mobile sensor terminal that moves in said measurement object space; and

measurement means that measures the position of said mobile sensor terminal, wherein

said fixed sensor terminal measures environmental conditions neighboring an installation location of a self-terminal,

said fixed sensor terminal and said mobile sensor terminal transmit or receive signals that perform positioning of the position of said mobile sensor terminal by wireless communication,

said positioning means performs positioning of the position of said mobile sensor terminal using the signals, and

said mobile sensor terminal measures environmental conditions neighboring the self-terminal while grasping the position of the self-terminal in said measurement object space using the positioning results.

22. The environment measurement system ofclaim 21, wherein

said mobile sensor terminal holds &list of measurement points whose environmental conditions in said measurement object space should be measured,

selects the measurement point whose environmental conditions needs to be measured next from said list,

decides movement amount of the self-terminal from the measurement point and the current position of the self-terminal based on positioning results of said positioning means to move to the measurement point, and

measures environmental conditions of the relevant measurement point.

23. The environment measurement system ofclaim 21, wherein

said mobile sensor terminal selects a measurement point whose distance from at least three or more said fixed sensor terminals is less than a predetermined threshold value as the measurement point whose environment conditions needs to be measured next when selecting the measurement point whose environment conditions needs to be measured next from said list.

24. The environment measurement system ofclaim 21, wherein

said fixed sensor terminal is installed in a region where said mobile sensor terminal has to measure environment conditions more frequently than the region where said mobile sensor terminal measures environment conditions.

25. An environment measurement system that measures environmental conditions of a measurement object space, comprising:

a plurality of mobile sensor terminals that move in said measurement object space; and

positioning means that measures the positions of said mobile sensor terminals, wherein

said positioning means selects one of said mobile sensor terminals as a position detection object terminal, and at the same time, selects other mobile sensor terminals as position detection standard terminals,

said position detection object terminal and said position detection standard terminals transmit or receive signals for positioning of said position detection object terminal through wireless communication,

said positioning means uses the signal to position said position detection object terminal, and

said position detection object terminal measures environment conditions neighboring the self-terminal while grasping the position of the self-terminal in said measurement object space using the positioning results.

26. The environment measurement system ofclaim 25, wherein

said position detection object terminal

holds a list of measurement points whose environmental conditions needs to be measured in said measurement object space,

selects the measurement point whose environmental conditions needs to be measured from said list,

decides the movement amount of the self-terminal from the measurement point and the current position of the self-terminal based on positioning results of said positioning means to move to the measurement point, and

measures environmental conditions of the relevant measurement point.

27. The environment measurement system ofclaim 25, wherein

said position detection object terminal selects the measurement point whose distances from at least three said position detection standard terminals are a predetermined value or less as a measurement point whose environmental conditions needs to be measured next when selecting a measurement point whose environmental conditions needs to be measured next from said list.

28. The environment measurement system ofclaim 25, wherein

said positioning means selects said mobile sensor terminal located furthest from the measurement point as said position detection object terminal after said position detection object terminal decides the measurement point whose environmental conditions needs to be measured next.

29. The environment measurement system ofclaim 25, wherein

said positioning means reselects one of said mobile sensor terminals as the position detection object terminal and reselects other mobile sensor terminals as position detection object terminals after said position detection standard terminal measures environmental conditions neighboring the self-terminal.

30. The environment measurement system ofclaim 25, wherein

said positioning means selects at least three said mobile sensor terminals whose distance from the measurement point is a predetermined threshold value or less as the position detection standard terminal after said position detection object terminal decides the measurement point whose environmental conditions needs to be measured next.

31. The environment measurement system ofclaim 21, wherein

said mobile sensor terminal holds a list in which a typical point of each region is made to be said measurement point as the list of the measurement point whose environmental conditions needs to be measured in said measurement object space upon partitioning said measurement object space into a lattice-shape region of a predetermined interval.

32. The environment measurement system ofclaim 21, wherein

said mobile sensor terminal holds a list in which a typical point of said lattice-shape region where no fixedly installed fixed sensor terminal exists is made to be the measurement point as the list of the measurement point whose environmental conditions needs to be measured in said measurement object space upon partitioning said measurement object space into a lattice-shape region of a predetermined interval.

33. The environment measurement system ofclaim 21, wherein

said mobile sensor terminal includes a mobile cart capable of moving on the two-dimension plane and a support table that supports a sensor for measuring environmental conditions of said measurement object space, and

a plurality of said sensors are provided on said support table along a vertical direction.

34. The environment measurement system ofclaim 21, wherein

each said sensor terminal performs wireless communication using an ultra wide band wireless signal.

35. The environment measurement system ofclaim 21, wherein

said positioning means detects the position of said mobile sensor terminal based on any of a received radio wave intensity, a radio wave propagation time, or a radio wave propagation time difference, or a combination thereof.

36. A facility management system, comprising:

the environment measurement system ofclaim 21, and

a facility management apparatus that controls operation of facility equipment, wherein

said facility management apparatus obtains measurement data of environmental conditions measured by said environment measurement system to control the operation of said facility equipment based on the measurement data.

37-39. (canceled)

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